Air conditioning system



July 6, 1937. B. P. FONDA AIR CONDITIONING SYSTEM Filed July 6, 1955 v INVENTOR. l .5 514x450 L B/VDA ATTORNEYS Patented July 6, 1937 UNITED STATES PATENT OFFICE.

AIR CONDITIONING SYSTEM Bayard P. Fonda, Cleveland, Ohio, assignor to The Bryant Heater Company, Cleveland, Ohio," a'. corporation of Ohio Application July 6, 1935, Serial No. 30,114

12 Claims.

This invention relates to improvements in air conditioning systems, and has reference particularly to systems in which provision is made for the dehumidification of air admitted to the system, especially where the control of the system is automatic.

One of the objects of the invention is the provision of means for insuring a substantially constant supply of fresh air, whether or not the dehumidifying means is in operation.

Another object is the provision in connection with such a system of means for conducting some predetermined proportion of the recirculated air through the dehumidifying means.

Still another object is the provision of a separate supply of fresh air to the system with automatic control of this supply as well as of the.

supply of dehumidified air.

Other objects and features of novelty will appear as I proceed with the description of those embodiments of the invention which for the pur- 'poses of the present application, I have illustrated in the accompanying drawing, in which Figs. 1, 2 and 3 are diagrammatic views illustrating different modifications of the system which is the subject of the invention, that of Fig. 2 being the preferred form.

Fig. 4 is a detail elevational view showing one form of humidostat which may be employed in connection with the invention.

Fig. 5 is a sectional detail view illustrating a damper construction which may be employed.

In the drawing a compartment in which air is to be conditioned is indicated at I0. An air duct ll carries the air into compartment l0, while air leaves compartment I 0 through a duct l2. The recirculating line for the compartment I0 includes besides the ducts H and I2 a duct 13 and a short connecting duct I4. In duct l3 there is an air cooler l5, which may consist of a coil of pip through which cool water is circulated. At

the junction of duct l3 with duct l I I have shown a blower l6, by means of which the circulation of air throughout the recirculating line l0, I2,

l4, l3, II, is effected. The above parts are identical in all of the three forms of 'theinvention here illustrated.

- Into this recirculating line at points which are spaced from each other to some extent at least,

I connect a conductor I1 and a conduit l8. In

the latter there is a dehumidifying means I9 and an air cooler 20, similar to the cooler IS. The dehumidifying means l9 comprises a body of solid adsorbent 2|, such as silica gel, activated alumina, or the like. Such an adsorbent has the property of removing moisture from the air, its action being to transform the latent heat from the moisture removed into sensible heat, which makes itself evident through an increase in the temperature of the air passing through the mathe dehumidifying means I use a humidostat 23,

which may be placed at an appropriate point in the line, that is'in the duct l2, or in the compartment Ill. The present invention is not concerned with the detail construction of the humidostat, but an example of a well known type is illustrated in Fig. 4, wherein a tape 24, which expands and contracts as the. humidity of the air in contact with it increases or decreases, is secured at one end in an adjustable anchoring means 25 and at the other end in a lever 26 pivotally mounted at 21. 28 and 29 are flexible electric conductors which have terminals in a mercury tube switch 30, which is tiltably mounted at 3| and is adapted to be swung to circuit closing position by the action of a spring 32 when the tape 24 expands to a predetermined extent due to a rise in humidity, and to circuit opening position by the contraction of tape 24 when the humidity falls sufliciently. I

The terminals 33 and 34 of the humidostat are connected by electric conductors 35 and 36 into one side of a line circuit comprising conductors 31 and 38 which lead to the motor of fan 22. Hence, when the humidity. in the recirculating line rises above a. predetermined level, the humidostat closes the circuit through conductors 31 and 38 and the electric fan 22 operates to induce flow of dehumidified air into the recirculating line; a

In the systems illustrated in Figs. 1 and 2 I have connected theair conductor I1 and the air conduit l8 by a shunt 3 9, which connects with the conduit ill on the rear side of the dehumidifier l9. This shunt connection has for one of itsv purposes permitting or causing a portion of the recirculating air to flow from the recirculating line through the conductor H to the left, through the dehumidifier l9, and back to the recirculating line. In order that the extent to which this occurs may be regulated to suit diiferent conditions or requirements, I provide a manually operated damper 40 in the conductor II in the case of the system illustrated in Fig. 1, and anautomatically I thereby increasing the suction eifect of fan 22 act-' ing through shunt 39. I prefer however to set damper 42 to admit a given quantity of tresh Air at all times and to use onlythe damper 40 or 4| for regulating the proportion of fresh and recirculated air entering the dehumidifier 9.

One of the functions of conductor I1 is to provide a .path of flow for fresh air to the recirculating line through ducts I4, I 3 and II when the dehumidifying means I9 is at rest, in other words when the fan 22 is not running. The resistance of the adsorbent 2| to the passage of airtherethrough is sufficiently great so that the blower l6 doesnot induce any appreciable flow of air through the dehumidifier. Hence, when the fan 22 was not running there would be no admission of fresh air to the recirculating line were it not for -the conductor I'I. At such times the suction of blower I6 is free to act upon conductor through duct |4- in the same way that it acts upon duct l2 through duct l4, that is if the dampers 40 or 4| are not closed. e

If in the case of Fig. l the damper 40 is open part-way, then fresh air will enter the dehumidi-.

fier through conduit 3, at the same time that recirculating air is being delivered to the dehumidifier from shunt 39 and conduit Onthe other hand when the fan 22 is not running fresh air will be by-passed around the dehumidifier, that is from conduit l8 through shunt 39 and conductor IT to ducts l4, l3 and H.

In Figs. 2 and 3the control of the damper 4| in conductor I1 is automatic, the damper being moved automatically toward closed position when the fan 22 is started, and being moved automatically toward open position when the fan 22 stops, all of these operations being under the control of the humidostat 23. The apparatus illustrated in the drawing is merely illustrative of one particular means for accomplishing this purpose. In this case, as shown particularly in Fig. 5, the damper 4| is pivotally mounted upon a shaft 43, which extends through the conductor H. To one end of the shaft exteriorly of the conductor there is attached a crank 44- to which is pivotally connected a link 45 that is pivoted to the lower end of a rod 46 that extends through a notch or hole in a bracket 41 which is secured to the conductor II. The rod 46 is threaded, and upon it are mounted two nuts 48 and 49, each of which may be adjusted to any desired position. The rod 46 is mounted in or fastened to the solenoid of an electromagnet '50, which is bridged across the electric line 31, 38. Obviously, when a circuit is set up through the line 31, 38 by the humidostat, the electromagnet 50 is energized and the damper 4| is closed to whatever extent the nut 48 will permit. On the other hand, when the electric circuit is broken, gravity will cause the rod 46 to descend until the nut 49 engages the top of bracket 41, and the damper 4| will be opened to a correspending extent. Fig. 3 differs from Fig. 2 by the omission of the shunt 39, and is the system employed when it is cooler l5 depended upon-exclusively for maintaining the desired temperaturein the compartment l0, .but the addition of cooler 20 is regarded as quite desirable because of the temperature rise imparted to the air in the dehumidifying operation.

In practice the amount of fresh air introduced into the system by the ,dehumidifying means may 'be suflicient, while that means is operating, to meet the ventilating requirements of compartment Ill. "The ventilating requirements remain the same, whether or not the dehumidifier is required to be in operation.' The apparatus employed in my system may be so adjusted, that when the dehumidifier is not in operation, a similar quantity of fresh air will be by-passed around the dehumidifier, as in Figs. 1 and 2, or drawn into the system independently of the dehumidifier. Hence, the supply of fresh air delivered to the compartment l0 may be made to be substantially constant regardless of' the operation of the dehumidifier.

Having thus described my invention, I claim:

1. In an air conditioning system, an air rethe air is to be conditioned, means for introducing dehumidified fresh air into saidline at a fixed rate, a humidostat in said line, means actuated by the humidostat for starting and stopping said first named means, and a conductor for by-passing fresh air around said dehumidifying means into said line at a fixed rate when said dehumidifying means is stopped.

2. In an air conditioning system, an,air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh air at a fixed rate into said line at a given point, a humidostat in said line, means actuated by the humidostat for starting and stopping said. first named means, and a conductor connecting the said line at a point spaced from said first named point with the intake side of said dehumidifying means, whereby a portion of the recirculating air may be dehumidified or whereby fresh air may be introduced into the line independently of said .dehumidifying means.

3. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh air at a fixed rate into said line at a given'point, a humidostat in said line, means actuated by the humidostat for starting and stopping said first named means, a conductor connecting the said line at a point spaced from dehumidifying means, whereby a portion of the recirculating air may be dehumidified or where- V by fresh air may be introduced into the line independently of said dehumidifying means, and means for varying the effective size of said con-'- ductor,

4. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh air into said line at a fixed rate, a humidostat in said line, means actuated by the humidostat for starting and stop- 'ping said first named means, a conductor for fresh air connected with said line at a point spaced from its connection with said dehumidifyingmeans and being connected at its opposite end with the intake of said dehumidifying means,

A and means for varying the effective size of said conductor. v

5. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh\ air into said line at a fixed rate, a humidostat' in said line, means accirculating line including a compartment in which tuated by the humidostat for starting and stop- 75 ping said first named means, a conductor for fresh air connected with said line at a point spaced from its connection with said dehumidifying means, said conductor being connected also with the intake side of said dehumidifying means,

a damper in said conductor, and means also controlled by said humidostat for causing said damper to assume either open or closed position.

6. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh air into said line at a fixed rate, means for starting and stopping said introducing means, a conductor for fresh air also connected with said line, a damper in said conductor, means for moving said damper from one setting to a different setting and vice versa, and a humidostat in said line, said humidostat being arranged to control the said damper and the said means for introducing dehumidified air.

7. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, means for introducing dehumidified fresh air into said line at a fixed rate. means for starting and stopping said introducing means, a' conductor for fresh air also connected with said line, a damper in said conductor, means for moving said damper from one setting to a difierent setting and vice versa, and a humidostat in said line, said humidostat acting when the humidity content is high to start said means for introducing dehumidified air. and to move said damper to its closed setting, and when the humidity content has decreased to a predetermined level to stop the means for introducing dehumidified air and to move the damper to its open setting.

8. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, a fresh air conduit having dehumidifying means therein connected with said line arranged to supply dehumidified air at a fixed rate, a fresh air conductor having'a damper therein also connected with said line, a humidostat in said line, and means controlled by said humidostat for starting the dehumidifying means and closingthe damper to a predetermined extent when the moisture content in the line rises above a predetermined level, and for stopping the dehumidifying means and opening the damper to a predetermined extent when the moisture con-- tent falls below said predetermined level.

9. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, a fresh air conduit having dehumidifying means therein connected with said line at a given point arranged to supply dehumidified air at a fixed rate, an air conductor having a damper therein connected with said line at a different point, a humidostat in said line, means controlled by said humidostat for starting the dehumidifying means when the moisture content'in the line rises above a predetermined level, and for stopping the dehumidifying means'wh'en the moisture content in the line falls below said predetermined level, said dehumidifying means including a fan for positively moving air toward the said recirculating line, said conduit and conductor being connected together upon the intake side of said dehumidifying means, whereby when said damper is moved to open position and said fan is not running the movement of air in said conductor is reversed.

10. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, a fresh air conduit having dehumidifying means therein connected with said line at a given point arranged to supply dehumidified air at a fixed rate, a fresh air conductor connected with said line at a different point, a humidostat in said line, means controlled by said humidostat for starting the,

dehumidifying means when the moisture content in the line rises above a predetermined level, and. for stopping the dehumidifying means when the moisture content falls below said predetermined level, said dehumidifying means including a fan for positively moving air toward the said recirculating line, a shunt between said conductor and conduit on the intake side of said dehumidifying means, and a damper in said conduit on the side of said shunt which is remote from said recirculating line, whereby the proportion of fresh air and recirculated air passing through the dehumidifying means may be'varied.

11. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, a fresh air conduit having a dehumidifying means therein connected with said line at a given point arranged to supply dehumidified air at a fixed rate, a fresh air conductor having a damper therein connected with said line at a different point, a

humidostat in said line, means controlled by said humidostat for starting the dehumidifying means and moving the damper in the direction of closed position to a predetermined setting when the moisture content inthe line' rises above a predetermined level, and for stopping the dehumidifying means and moving the damper toward open position to a predetermined setting when the moisture content in the line falls below said predetermined level, saidvdehumidifying meansincluding a fan for positively moving air toward the said recirculating line, and a shunt. connecting said conduit and conductor on the intake side of said dehumidifying means.v

12. In an air conditioning system, an air recirculating line including a compartment in which the air is to be conditioned, a fresh air conduit having a dehumidifying means therein connected with said line at a given point arranged to supply dehumidified air at a fixed rate, afresh air conductor having adamper therein connected with said line at a difierent point, a humidostat in said line, means controlled by said humidostat for starting the dehumidifying means and moving the damper in the direction'of closed position to a predetermined setting when the moisture content in the line rises above a predetermined level, and for stopping the'dehumidifying .means and moving the damper toward open position to a predetermined setting when the moisture content in the line falls below said predetermined level, said dehumidifying means including a fan for positively moving air toward the said recirculating line, a, shunt connecting said, conduit and conductor on the intake side of said dehumidifying means, and a damper in said conduit on the side of said shunt which is remote from said recirculating line.

' BAYARD P. FONDA. 

